3,346 research outputs found
Microbial communities and bioactive compounds in marine sponges of the family Irciniidae-a review
Marine sponges harbour complex microbial communities of ecological and biotechnological importance. Here, we propose the application of the widespread sponge family Irciniidae as an appropriate model in microbiology and biochemistry research. Half a gram of one Irciniidae specimen hosts hundreds of bacterial species-the vast majority of which are difficult to cultivate-and dozens of fungal and archaeal species. The structure of these symbiont assemblages is shaped by the sponge host and is highly stable over space and time. Two types of quorum-sensing molecules have been detected in these animals, hinting at microbe-microbe and host-microbe signalling being important processes governing the dynamics of the Irciniidae holobiont. Irciniids are vulnerable to disease outbreaks, and concerns have emerged about their conservation in a changing climate. They are nevertheless amenable to mariculture and laboratory maintenance, being attractive targets for metabolite harvesting and experimental biology endeavours. Several bioactive terpenoids and polyketides have been retrieved from Irciniidae sponges, but the actual producer (host or symbiont) of these compounds has rarely been clarified. To tackle this, and further pertinent questions concerning the functioning, resilience and physiology of these organisms, truly multi-layered approaches integrating cutting-edge microbiology, biochemistry, genetics and zoology research are needed.Portuguese Foundation [PTDC/MAR/101431/2008, PTDC/BIA-MIC/3865/2012]; European Regional Development Fund (ERDF) through the Operational Competitiveness Programme (COMPETE); national funds through FCT (Foundation for Science and Technology) [PEst-C/MAR/LA0015/2011]; FCT [SFRH/BD/60873/2009]info:eu-repo/semantics/publishedVersio
Farmers Markets and the Local Food System: The Case of Gettysburg, Pennsylvania
In order to examine and obtain a better understanding of the local food system within Adams County, Pennsylvania, this study explores the characteristics and perspectives of the customers and vendors at the farmers markets in Gettysburg, Pennsylvania. Survey findings from the Gettysburg Farmers Market and the three Adams County Farmers Markets include customer demographic information, perspectives and shopping behavior as well as vendor product information, farm size and location and preference for market management. Introductory background information on the Farm Bill and the influence of agricultural practices on the environment, human health and nutrition and the relationship between farmers markets and the local economy are offered in order to emphasize the value of a well-managed local food system. Conclusions provide evidence that lower income and lower education levels are not sufficiently represented at all the markets and food stamp programs are being underutilized. This study suggests employing additional marketing to target underrepresented demographic groups, public transportation to potentially inaccessible market locations and increased advertisement and encouragement of food stamp programs at all markets in order to expand the customer base and increase access to healthy, local foods for less advantaged citizens. The results from this study are intended to offer evidence that will promote and facilitate market management, strengthen customer/vendor relationships and encourage better ties between the local community and local food systems at the farmers markets within Gettysburg in Adams County, Pennsylvania
Recurrent strokes under anticoagulation therapy: Sticky platelet syndrome combined with a patent foramen ovale
The sticky platelet syndrome (SPS) is a congenital disorder characterized by platelet hyperaggregability to epinephrine and/or adenosine diphosphate; this predisposes affected individuals to acute myocardial infarction, ischemic optic neuropathy, recurrent venous thromboembolism, and transient ischemic cerebral attacks and strokes. Here, we describe an unusual case with recurrent cerebrovascular accidents due to SPS, in the presence of a patent foramen ovale (PFO). We report an unusual case of a 56-year-old female patient with a PFO, who suffered from recurrent strokes despite long-term medication with clopidogrel for SPS. The patient underwent successful transcatheter closure of the PFO, and, in addition, she has been placed on low-dose acetylsalicylic acid. After 18-month follow-up, she demonstrated an intact atrial septum without any vegetations on the percutaneous device until today. She has had no further thromboembolic events
S, Cl and F degassing as an indicator of volcanic dynamics: The 2001 eruption of Mount Etna
IBIS preliminary results on Cygnus X-1 spectral and temporal characteristics
We report preliminary results of a broadband spectral and temporal study of
the black-hole binary Cyg X-1 performed with the IBIS telescope. Cyg X-1 was
the first pointed celestial target of IBIS during the INTEGRAL Performance and
Verification Phase, 2002 Nov.-Dec., for a total observing time of 2 Ms in both
staring and dithering mode. Here, we report on only the staring, on-axis,
observation performed in a stable instrument configuration. During the
observing period the source was in its characteristic low/hard state, in which
a few flares and dips have been detected. The IBIS/ISGRI results demonstrate
that the INTEGRAL observatory offers a unique capability for studying
correlations between hardness and/or flux in different bands over a wide photon
energy range. One of our new results is finding that the hardness-flux
correlation changes the sign twice over the 20-220 keV; first from positive to
negative at 50 keV, and then back to positive at 120 keV. The former change
appears to be due to the spectral curvature introduced by variable Compton
reflection. The latter may be due spectral pivoting.Comment: 7 pages, 8 figures (4 in color), accepted for publication in A&A,
INTEGRAL special issu
Human and animal integrated influenza surveillance: a novel sampling approach for an additional transmission way in the aquatic bird reservoir.
Background: infectious low pathogenic avian influenza viruses (LPAIVs) have been recently detected
on feathers of wild ducks. Laboratory trial results suggested that the preen oil gland secretion,
covering waterbirds\u2019 feathers, may attract and concentrate virus particles from AIV-contaminated
waters to birds\u2019 bodies. We evaluated whether ducks can become infected by the ingestion of preen
oil-associated viral particles, experimentally smeared on their plumage. In addition, we compared
virologic and serologic results obtained from mallards whose feathers were experimentally infected,
with those from wild mallards naturally carrying AIVs on feathers.
Methods: we experimentally coated 7 mallards (Anas plathyrynchos) using preen oil mixed with
a LPAIV (H10N7 subtype), and housed them for 45 days with a control, uncoated duck. Cloacal,
oropharyngeal and feather swabs were collected from all birds and examined for AIV molecular
detection and isolation. Blood samples were also taken to detect influenza specific antibodies. In
addition, sera from 10 wild mallards, carrying on feathers infectious LPAIV H10N7, were examined.
Results: virologic and serologic results indicated that through self- and allopreening all the birds
experimentally coated with the preen oil/AIV mix and the control duck ingested viruses covering
feathers and became infected. Virus isolation from feathers was up to 32 days post-coating treatment.
One out of 8 wild mallards showing antibodies against type A influenza virus was seropositive for H10
subtype too.
Conclusions: our experimental and field results show evidences suggesting that uninfected birds
carrying viruses on their feathers, including immune ones, might play an active role in spreading AIV
infection in nature. For this reason, routine AIV surveillance programs, aimed at detecting intestinal
and/or respiratory viruses, should include the collection of samples, such as feather swabs, enabling
the detection of viruses sticky to preened birds\u2019 bodies
Testing current synthesis models of the X-ray background
We present synthesis models of the X-ray background where the available X-ray
observational constraints are used to derive information on the AGN population
properties. We show the need for luminous X-ray absorbed AGNs, the QSO2s, in
reproducing the 2-10 keV source counts at relatively bright fluxes. We compare
a model where the evolution of absorbed AGNs is faster than that of unabsorbed
ones, with a standard model where absorbed and unabsorbed AGNs evolve at the
same rate. It is found that an increase by a factor of ~2 from z=0 to z~1.3 in
the ratio between absorbed and unabsorbed AGNs would provide a significant
improvement in the data description. Finally, we make predictions on the AGNs
to be observed in deep X-ray surveys which contain information on the AGN space
density at high redshift.Comment: 11 pages with 8 figures, A&A accepte
Chromatic Illumination Discrimination Ability Reveals that Human Colour Constancy Is Optimised for Blue Daylight Illuminations
The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed
Resolving the Composite Fe K-alpha Emission Line in the Galactic Black Hole Cygnus X-1 with Chandra
We observed the Galactic black hole Cygnus X-1 with the Chandra High Energy
Transmission Grating Spectrometer for 30 kiloseconds on 4 January, 2001. The
source was in an intermediate state, with a flux that was approximately twice
that commonly observed in its persistent low/hard state. Our best-fit model for
the X-ray spectrum includes narrow Gaussian emission line (E = 6.415 +/- 0.007
keV, FWHM = 80 (+28, -19) eV, W = 16 (+3, -2) eV) and broad line (E = 5.82
(+0.06, -0.07) keV, FWHM = 1.9 (+0.5, -0.3) keV, W = 140 (+70, -40) eV)
components, and a smeared edge at 7.3 +/- 0.2 keV (tau ~ 1.0). The broad line
profile is not as strongly skewed as those observed in some Seyfert galaxies.
We interpret these features in terms of an accretion disk with irradiation of
the inner disk producing a broad Fe K-alpha emission line and edge, and
irradiation of the outer disk producing a narrow Fe K-alpha emission line. The
broad line is likely shaped predominantly by Doppler shifts and gravitational
effects, and to a lesser degree by Compton scattering due to reflection. We
discuss the underlying continuum X-ray spectrum and these line features in the
context of diagnosing the accretion flow geometry in Cygnus X-1 and other
Galactic black holes.Comment: Accepted for publication in Ap
Antiplatelet agents for chronic kidney disease
To evaluate the benefits and harms of antiplatelet therapy in patients with any form of kidney disease, including patients with CKD not receiving renal replacement therapy (RRT), patients receiving any form of dialysis, and kidney transplant recipients
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